1. Field of the Utility Model
The present invention generally relates to a signal transmission circuit structure, and more particularly, to a gate signal transmission circuit structure disposed on a peripheral circuit region of a display panel.
2. Description of Related Art
Along with the rapid progress of the image display technology, a common TV set or a computer monitor has evolved to the current liquid crystal display (LCD) from the cathode ray tube (CRT) display. A liquid crystal display panel (LCD panel) employed by an LCD is usually composed of an active device array substrate, an opposite substrate and a liquid crystal layer disposed between the above-mentioned two substrates. In addition, sealant is used to adhere the two substrates to avoid the liquid crystal from flowing out.
In general speaking, an active device array substrate can be divided into an active region and a peripheral circuit region. A plurality of pixels are disposed in the active region to form a pixel array, while a peripheral circuit is disposed in the peripheral circuit region, wherein each pixel includes a thin film transistor (TFT) and a pixel electrode connected to the TFT, and each pixel is enclosed by and electrically connected to two adjacent scan lines and two adjacent data lines. These scan lines and data lines extend from the active region to the peripheral circuit region so as to connect the above-mentioned peripheral circuit. Further, the peripheral circuit is connected to an external driver IC so as to drive the pixels in the active region.
The peripheral circuit includes a plurality of driver bonding pads and a plurality of transmission lines directly electrically connected to the driver bonding pads. The driver bonding pad is mostly composed of a plurality of pads comprising a plurality of metal layers and insulation layers stacked by each other and a patterned transparent conductive layer overlaying the pads. During forming the peripheral circuit, it is required to fabricate the patterned transparent conductive layer overlaying the pads so that an etching liquid with corrosive is used to perform a patterning process on the transparent conductive layer. However, during performing the patterning process, it often produce transition etching or corrosion on the pads under the transparent conductive layer, and meanwhile, it may directly lead to corrosion on the transmission lines connected to the driver bonding pads. Moreover, when or after other processes, the influence of the external environment may also cause corrosion (by, for example, high temperature or high moisture). When the corrosion area is too large, an abnormal signal is produced, which further affects the display quality of the display panel.